Comments

They don't sound alike? Wow, have I been pronouncing them incorrectly the entire time? Or perhaps it's a dialect difference? I've certainly always pronounced "ingenious" (not to be confused with "ingenuous", of course) pretty much exactly the way I pronounce "genius", except with an "in-" at the beginning.

It gets even more complicated (sticky in both root and meaning) when you throw "ingenuous" into the mix; an example of language as some sort of devil's whore and complicated to teach. Different roots all.

But (the inimitable) languagehat addresses this by way of OED cut/paste here: